With the rapid development and popularization of mobile terminals, uplink and downlink data rates supportive to wireless networks increase by times, and mobile phones that were used merely for communication now advance rapidly and show many capabilities in new applications, especially in the aspect of data services. Mobile phone has become an indispensable information terminal, and more and more people use mobile phones as a replacement for computer, camera and electronic book. The appearance of wireless interconnection techniques makes mobile phones much smarter, and using wireless networks to acquire information has become the most important purpose of a terminal user. Wireless networks and mobile terminals are used for information inquiry, social contacts, shopping and navigation, thus greatly improving user experience.
Information is various and massive nowadays, more and more attentions are paid to privacy in social networks; as information spreads unchecked, users put forward higher and higher privacy protection demands because users cannot be much relaxed unless during a private chatting process, and information including pictures, words and voice needs to be kept private. Based on these demands, privacy protection becomes the general trend. The more rampant social contacts are, the greater the potential of privacy applications is. As an embodiment of a privacy application, Wechat only permits friends to view comments in the Moments, and merely by means of this function, Wechat is quite satisfactory to users. In interactions over social networks, more and more attentions are focused on the privacy of information, a picture shared with friends will be deleted automatically within 10 seconds or a shorter time after the picture is received by a friend, this is Snapchat.
However, the privacy function of existing social software, for example, Snapchat, has severe functional defects because the user of a mobile phone can store the pictures, words or videos displayed on the current screen by implementing a screen capturing operation using the screen capturing function of the mobile phone or a computer-side tool connected with the mobile phone without being perceived by the opposite-end user. This causes a risk to the privacy of the user of existing social software. How to avoid this risk is the technical problem the present disclosure is intended to address.